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As a result, the dust, and the very front layers of the retroreflector prisms, heat up on the day of the full Moon. In response to the temperature gradient across the prisms, both the shape and the homogeneity of the glass from which the prisms are made are compromised. This thermal response has rather the same effect as placing a very weak lens on the front of the retroreflectors.
This lensing effect defocuses the otherwise parallel light that emerges from the retroreflectors, making the return spot size larger on the Earth's surface.
The telescope, which is tiny compared to the area over which the laser photons are returned to the Earth, therefore sees a smaller proportion of those photons. This decrease is expected only during full Moon. It's a nice idea, but rather difficult to prove without going to the Moon's surface and making measurements. Murphy had an idea.
If the Sun's heat was distorting the retroreflectors at full Moon, all he had to arrange to test that was to turn off the Sun, and see if the signal comes back. Although turning off the Sun is a bit tricky, it happens naturally on the Moon's surface when we see a lunar eclipse.
At that point, the Earth blocks the Sun's light from striking the Moon. Naturally, all lunar eclipses occur at full Moon. Murphy's team eventually had good conditions for lunar ranging during a lunar eclipse. During the five and a half hour duration of the eclipse a lunar eclipse is far longer than a solar eclipse, essentially because the Earth is larger than the Moon , the team reflected pulses from all the lunar retroreflectors. Before the eclipse, they saw the usual tenfold reduction in signal. When the progress of the eclipse put each retroreflector into the dark in turn, the full return signal returned.
Finally, when the Sun again shone on the lunar surface, the signals fell to their usual full Moon level. While these observations remain something short of complete proof of the mechanism, it does appear to confirm the effect is driven by the Sun's heating of the lunar apparatus.
While the lunar ranging Full-Moon Curse is now put to bed, it is an important reminder that just because something happens on a apparently supernatural schedule doesn't mean it can't be real. The lunar retroreflector left behind by Apollo 15 Photo: The thermally distorted retroreflector on the right causes about 90 percent of the reflected photons to be missed by the Apache Ridge telescope Image: A pair of nm laser beams rising toward the retroreflectors on the lunar surface Photo: Lunar ranging laser pulse scattering off high terrestrial cloud during eclipse Photo: NASA The thermally distorted retroreflector on the right causes about 90 percent of the reflected photons to be missed by the Apache Ridge telescope Image: Dodson A pair of nm laser beams rising toward the retroreflectors on the lunar surface Photo: Over , people receive our email newsletter See the stories that matter in your inbox every morning Your Email.
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Juno approaches halfway mark of its science mission. Virgin Galactic might reach space on next flight. If only all stretch goals were as good as this. Ritual of the Night on KickStarter, Curse of the Moon looks and plays like a classic 8-bit game that never existed. This, however, bears all the hallmarks of a developer determined to redeem itself.
While it appears Igarashi only had a supervisory role—which almost certainly involved little more than the occasional approving nod—Curse of the Moon offers more than a passing wink to the series with which he made his name. In fact, it bears more than a few similarities to one particular Castlevania game. As in Castlevania III: Miriam wields a whip, jumps high and can slide under low ceilings.
Arthur, an alchemist, uses powerful magic his flame barrier is hilariously overpowered , while vampire Gebel can transform into a bat, crossing long, platform-free chasms. A key difference is that you can switch between all four at will, rather than being limited to bringing just a single ally with you.
You have separate health gauges, too—essentially giving you four lives to complete a stage. And a Casual difficulty option not only gives you infinite lives, but stops you from being pushed back when you take damage—thus avoiding the frustration of having your favourite character nudged into a void by a flying pest just before the boss screen. Even those with little experience of the classics should be able to reach the end within two hours or so.